Spring-tool.



PATENTED AUG. 11, 1908.

' W. AVERY.

SPRING TOOL.

WITNESSES- 5 W away UNITED STATES PATENT ()FFICE.

ll/LIAM AVERY, OF JAUAIGA PLAIN, MASSACHUSETTS.

SPRING-TOOL.

which takes place between the members of said toolsupon their first contact with the work and second, to rigidly fix a removable cutter to the front member of the tool. I attain these objects by the mechanism illustrated in the accompanying drawings, in

. which Figure 1, is a perspective view of the tool.

Fig. 2, is a front elevation of the same. Fig. 3, is a partial plan of the underside. Fig. 4,

is a partial sectional view on line 4, 4, Fig. 2, F ig. 5, is an elevation of acutter for screws, or the base for other tool forms which may be made integral withit.

The body of the tool 1 is of the proper size to be clamped in the tool-post of the lathe, or other machine in which it is to be used. Projecting above the body 1 there is the spring portion 2, which in turn carries the cutter clamping device 3, the whole being made integral. A slot 4 is out between the two parts of the tool, the width of which limits the movement of the spring 2 and the lower part of the clamp 3 is cut away at 5 sufficient to allow this movement without contacting with the base of the tool-post.

As thus far described this tool is substantially the same as those known to the art, and would operate in substantially the-same manner. That is, when the cutter first contacts with the work, or when it strikes a part of the metal which is harder than the rest, a slight lateral movement will take place between the parts I and 3, which causes the cutter to slightly fall behind the position due to the fixed forward movement given to the tool by the action of the feeding-mechanism. The defect of this movement of the parts of the tool is most obvious when it is used for the cutting of threads or screws, where to secure a perfect I it a portion of the first thread has to be removed, To remedy this fault and assure perfect lateral rigidity to the cut- Specification of Letters 'Patent'.

Application filed December '7, 1904. Serial No. 235,892.

Patented Aug. 11, 1908.

for the move 6 is made in the underside of the tool, as shown by Figs. 3 and t, and the metal-strip 7 is fitted to the. sides of the groove and secured to the part 1 the forward end of the strip being rounded and spaced sufficient to allow the vertical spring movement of the part 3. This prevents all lateral movement of the parts 1 and 3 and causes the cutter to stand up to the work with the same rigidity it would in a tool without the spring device, and at the same time combines therewith the full benefit of the spring.

The clamp 23 for the base of the removable cutter is made with projecting lips under-cut to the angle of the 'V-thread, which is sixty degrees. The sides of the lips are made slightly tapering, being made narrowest at the underside of the clamp, and the base of the removable cutter is made of corresponding taper, as shown by Fig. 5, where the cutter and its base are shown as a thread-tool.

To provide for the movement of the cutter clamp the slot 8 is cut substantially parallel to the center of the clamp, and when the cutter is placed in the clamp the operation ofthe screw 9 rigidly clamps said cutter, and the action of the ta )er prevents any longitudinal movement of the base of the cutter in the clamp.

The operation of this spring-tool will be clearly understood by those skilled in the art, and it is of special value in the cutting of the thread on taps, for the removable cutter can be removed and sharpened for the last cuts and replaced accurately without removing the body of the tool from its fixed position in the tool-post.

By the drawings, especially Fig. 5 it will be seen that the taper of the cutter, and of course, the inner sides of the clamp is very little, not exceeding two-onehundredths (2/100) of an inch to an inch of length of the cutter, and that a very slight movement of the screw 9 will suffice for a long range of vertical movement of the cutter.

What I claim, and desire to secure by Letters Patent of the United States, is

1. A spring-tool comprising a body, a spring arranged to yield to the thrust of the Work, a cutter-clamp integral therewith and means to prevent lateral movement of the cutter-clamp relative to the body.

2. A sprmg-tool comprising a body, a

spring arranged to yield to the thrust of the to prevent lateral movement of the clamping 10" work, a cutter-clamping device integral devic e relative to the body. therewith and means to prevent lateral In testimony whereof I have signed my movement of the clamping device relative name to this specification in thepresence of therewith and a tongue and groove 6 and 7 to the body. I two subscribing Witnesses.

'3. A spring-tool comprising a body, .a WILLIAM AVERY. spring arranged to yield to the thrust of the Witnesses I work, a cutterclamping device integral FRANK G. PARKER,

JOHN BUCKLER. 

